نتایج جستجو برای: sorbic acid
تعداد نتایج: 747453 فیلتر نتایج به سال:
The spoilage yeast Saccharomyces cerevisiae degraded the food preservative sorbic acid (2,4-hexadienoic acid) to a volatile hydrocarbon, identified by gas chromatography mass spectrometry as 1,3-pentadiene. The gene responsible was identified as PAD1, previously associated with the decarboxylation of the aromatic carboxylic acids cinnamic acid, ferulic acid, and coumaric acid to styrene, 4-viny...
Sorbic acid was added to wines in different concentrations to determine its effect on the inhibition of yeasts in semi sweet wines. Sorbic acid proved to be an effective inhibitor of yeast growth when used at a concentration of 200 mgle in conjunction with a concentration of 100 mg S02IC. As the sorbic acid does not kill the yeast cells but only inhibits them it is imperative that the wine shou...
The behavior of sorbic acid in model systems comprised of concentrated sugar solutions (water activity 0.94) at pH 3.5 and 4.5 was studied. Sorbic acid degraded appreciably as a function of time and temperature during storage and its destruction could be described by first-order kinetics. The rate constants of sorbic acid destruction were found to be related to composition of the sugar model sy...
A simple, sensitive and specific HPLC method was validated for the simultaneous determination of benzoic acid and sorbic acid in noodles. Sample preparation involved the extraction with methanol and water (60:40, v/v). The separation was achieved on a GerminiC18 modified silica column (50 mm x 4.6 mm i.d., 5 μm particle diameter). The mobile phase consisted of 0.05 M ammonium acetate (pH 4.4) a...
Sorbic hydroxamic acid was prepared from sorbic acid by esterification and treatment with hydroxylamine (mp 133 to 135 C, pK(a) 8.8). Its ultraviolet spectrum in acid solution had a single absorption maximum at 262 mmu; in alkaline solution the maximal absorption shifted to 255 mmu and significant absorption appeared at 280 to 300 mmu. At concentrations of 0.1% (w/v), sorbic hydroxamic acid pre...
The growth of the filamentous fungus Aspergillus niger, a common food spoilage organism, is inhibited by the weak acid preservative sorbic acid (trans-trans-2,4-hexadienoic acid). Conidia inoculated at 10(5)/ml of medium showed a sorbic acid MIC of 4.5 mM at pH 4.0, whereas the MIC for the amount of mycelia at 24 h developed from the same spore inoculum was threefold lower. The MIC for conidia ...
York, George K. (University of California, Davis), and Reese H. Vaughn. Mechanisms in the inhibition of microorganisms by sorbic acid. J. Bacteriol. 88:411-417. 1964.-Oxidative assimilation of glucose, acetate, succinate, and fumarate by washed cells of Escherichia coli, Pseudomonas aeruginosa, and Saccharomyces cerevisiae was inhibited by concentrations of sorbic acid ranging from 15 to 105 mg...
The weak acid sorbic acid transiently inhibited the growth of Saccharomyces cerevisiae in media at low pH. During a lag period, the length of which depended on the severity of this weak-acid stress, yeast cells appeared to adapt to this stress, eventually recovering and growing normally. This adaptation to weak-acid stress was not due to metabolism and removal of the sorbic acid. A pma1-205 mut...
Previous studies (Costilow et al., 1955) demonstrated that the yeasts found to be most prevalent in cucumber fermentations were completely inhibited by 0.01 per cent sorbic acid in an 8 per cent salt (NaCl) medium at pH 4.6. As the pH was increased and/or the salt concentration decreased, more sorbic acid was required for complete inhibition of some of the yeasts tested. Cultures of Pediococcus...
Sorbic acid and acetic acid are among the weak organic acid preservatives most commonly used to improve the microbiological stability of foods. They have similar pKa values, but sorbic acid is a far more potent preservative. Weak organic acids are most effective at low pH. Under these circumstances, they are assumed to diffuse across the membrane as neutral undissociated acids. We show here tha...
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